This is in support of Max's series to split vfio-pci. For that to work the reflck concept embedded in vfio-pci needs to be sharable across all of the new VFIO PCI drivers which motivated re-examining how this is implemented.
Another significant issue is how the VFIO PCI core includes code like:
if (pci_dev_driver(pdev) != &vfio_pci_driver)
Which is not scalable if there are going to be multiple different driver types.
This series takes the approach of moving the "reflck" mechanism into the core code as a "device set". Each vfio_device driver can specify how vfio_devices are grouped into the set using a key and the set comes along with a set-global mutex. The core code manages creating per-device set memory and associating it with each vfio_device.
In turn this allows the core code to provide an open/close_device() operation that is called only for the first/last FD, and is called under the global device set lock.
Review of all the drivers show that they are either already open coding the first/last semantic or are buggy and missing it. All drivers are migrated/fixed to the new open/close_device ops and the unused per-FD open()/release() ops are deleted.
The special behavior of PCI around the bus/slot "reset group" is recast in terms of the device set which conslidates the reflck, eliminates two touches of pci_dev_driver(), and allows the reset mechanism to share across all VFIO PCI drivers. PCI is changed to acquire devices directly from the device set instead of trying to work backwards from the struct pci_device.
Overall a few minor bugs are squashed and quite a bit of code is removed through consolidation.
v2: - Reorder fsl and mbochs vfio_uninit_group_dev - Fix missing error unwind in mbochs - Return 0 from mdev open_device if there is no op - Fix style for else {} - Spelling fix for singleton - Acquire cur_mem under lock - Always use error unwind flow for vfio_pci_check_all_devices_bound() v1: https://lore.kernel.org/r/0-v1-eaf3ccbba33c+1add0-vfio_reflck_jgg@nvidia.com
Jason Gunthorpe (12): vfio/samples: Remove module get/put vfio/mbochs: Fix missing error unwind in mbochs_probe() vfio: Provide better generic support for open/release vfio_device_ops vfio/samples: Delete useless open/close vfio/fsl: Move to the device set infrastructure vfio/platform: Use open_device() instead of open coding a refcnt scheme vfio/pci: Change vfio_pci_try_bus_reset() to use the dev_set vfio/pci: Reorganize VFIO_DEVICE_PCI_HOT_RESET to use the device set vfio/mbochs: Fix close when multiple device FDs are open vfio/ap,ccw: Fix open/close when multiple device FDs are open vfio/gvt: Fix open/close when multiple device FDs are open vfio: Remove struct vfio_device_ops open/release
Max Gurtovoy (1): vfio: Introduce a vfio_uninit_group_dev() API call
Yishai Hadas (1): vfio/pci: Move to the device set infrastructure
Documentation/driver-api/vfio.rst | 4 +- drivers/gpu/drm/i915/gvt/kvmgt.c | 8 +- drivers/s390/cio/vfio_ccw_ops.c | 8 +- drivers/s390/crypto/vfio_ap_ops.c | 8 +- drivers/vfio/fsl-mc/vfio_fsl_mc.c | 158 ++---- drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c | 6 +- drivers/vfio/fsl-mc/vfio_fsl_mc_private.h | 7 - drivers/vfio/mdev/vfio_mdev.c | 31 +- drivers/vfio/pci/vfio_pci.c | 457 ++++++------------ drivers/vfio/pci/vfio_pci_private.h | 7 - drivers/vfio/platform/vfio_platform_common.c | 86 ++-- drivers/vfio/platform/vfio_platform_private.h | 1 - drivers/vfio/vfio.c | 151 +++++- include/linux/mdev.h | 9 +- include/linux/vfio.h | 26 +- samples/vfio-mdev/mbochs.c | 23 +- samples/vfio-mdev/mdpy.c | 40 +- samples/vfio-mdev/mtty.c | 40 +- 18 files changed, 444 insertions(+), 626 deletions(-)